At least eight people were killed Monday and early Tuesday in U.S. airstrikes targeting al-Shabab militants in southern Somalia.

Pentagon spokesman Captain Jeff Davis said unmanned drones were used in the attacks.

Witnesses and officials told VOA's Somali service that five militants and three civilians were killed in the airstrikes, which hit the al-Shabab-controlled village of Yontoy in Somalia's Lower Juba region.

The Pentagon spokesman put the death toll at 12 militants. He described the airstrikes as "self-defense," saying the targets of the attack "were posing an imminent threat to U.S. personnel."

It was not immediately known whether any al-Shabab leaders were hit. A high-ranking security official in Kismayo told VOA that al-Shabab militants were seen making “some movements” before the airstrike.

Yontoy is about 24 kilometers north of the coastal city of Kismayo. Officials suspect the village serves as a launching post for al-Shabab militants who attack Kismayo's airport with mortars.

The U.S. has repeatedly used drones to attack al-Shabab. The group's longtime leader, Ahmed Abdi Godane, was killed by a U.S. drone strike in September 2014.

VOA National security correspondent Jeff Seldin contributed to this report.